Drop-hammer board



Mar. 3. 1925. v

. J. BURGER- DROP HAMMER BOARD Filed July 23, 1923 Patented Mar. 3, 1925.

Pa o FFI R BrII AMMEB: 1304BQ- Application filed July 23, 1923. Serial No: 653,209.

To all whom it maggoncerm Be it known that I JZOHlYyA-,BURGER, a citizen of the United States of America, residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in Drop- I-Iammer Boards, of which the following is a specification, reference being had therein to the accompanying drawings.

In my Patent No. 901,779, granted Octoher 20, 1908, there is disclosed a frictionboard for drop-forging hammers and the board is composed of two flat thin strips secured together in a manner to prevent splitting, cracking, or breaking and at the same time lend a degree of strength and elasticity to the board and thereby increase its period of usefulness compared to an ordinary wooden strip as commonly used. 7 On account of the strips being wide it was necessary to use a No. 1 wood and even then weak spots would often develop and the life of the board would be comparatively short. Wood strips for such wide boards are becoming more and more difficult to obtain without imperfections and consequently the cost of such boards is increasing and a cheaper.

board must be found.

My invention aims to provide a built up board, that is, a board composed of a multiplicity of strips, each of small cross sectional area. Such strips can be more easily obtained in perfect form for the purpose of a drop hammer board, and if a strip should develop a weak spot or some imperfection that would render the board imperfect as a whole, the strip can be removed and another substituted therefor, thus saving the greater part of the board.

My invention also aims to fabricate a drop hammer board in such a manner that the component parts of the board will be more durable and possess greater elasticity than if a single piece of material is used to form the board.

My board will be hereinafter described Fig. 2. is a vertical sectionalvview of the S ect; j

Fig. 3 is a perspective view of a portion of a board of one form, and

Fig. 4 is a similar view of a board of another form.

As illustrating the manner in which a board in accordance with my invention may berused, I have shown a conventional form of drop hammer 1 having an upper die or head 2 to which my board is attached, the board extending between friction rollers 3 adapted to be driven to raise the board and die attached thereto and then release the board so that the die may descend by gravity and cause work to be-performed by the drop hammer.

As mentioned in the beginning the board is built up from a multiplicity of strips, in contradistinction to a one-piece board or a board composed of two. flat strips, such as disclosed in my prior patent.

One form of the board, as shown in Fig. 3, includes two laminations with a strip of leather 4 Mother flexible material sandwich-ed therebetween and to which strip may be glued or otherwise secured the faces 5 of bars or planks 6 composing each lamination, said bars or planks being substantially rectangular in cross section with confronting walls thereof in abutting relation and suitably connected together. The bars or planks are comparatively narrow and such configuration permits of bars or planks being selected that are entirely devoid of any weak spotsor imperfections that would re duce the strength and flexibility of the board as an entirety.

Another form of board is shown in Fig. 4 where strips of leather 7 or other flexible material is sandwiched between the confronting walls of the bars or planks of each lamination and in this form of board there may be a greater degree of flexibility than that shown in Fig. 3. In either instance, should one of the bars or planks be injured such injured bar or plank can be removed and a perfect bar or plank substituted therefor, without discarding the remainder of the board.

Since it is comparatively easy to obtain perfect stock in small quantities and sizes,

it is obvious that my improved boards can be produced at less expense and with less trouble than that of boards made of wide strips, such as disclosed in my prior patent.

I reserve the right to employ any means, mechanical or otherwise for holding the bars or planks assembled to form the laminated board, and while in the drawing there are illustrated the preferred embodiments of my invention, it is to be understood that such changes may be made as are permissible by the appended claims.

What I claim is 1. As a new article of manufacture, a drop hammer board composed of laminations,

' said bars.

2. A drop hammer board composed of laminations, a flexible strip of material between said laminations, each lamination composed of parallel bars, and strips of material between adjacent faces of said bars.

In testimony whereof I afiiX my signature in the presence of two witnesses.

JOHN A. BURGER. 

